Because you think EVs keep the planet alive? They require enormous amounts of raw materials. Unless they are also shared with car sharing or car pooling. Then yes.
The studies say with an EV you come to break-even after two years of usage. This is with today's technologies of course. So if you buy a EV now, only in two years you can claim you were greener than an ICE. But after that, it does its job. Now of course the right way would be to use public transport but I guess some people will care even less about such a strange idea. Yes I am aware in some countries or places PT is not there. But anything can be done if there's a will, so not having public transport in place X means only not enough people wanted to have public transport in place X.
With "an" EV? Like all EVs have the same carbon footprint? That's definitely not true. Furthermore, even an EV has a carbon footprint and its far from 0. The real solution to be greener is to walk, ride a bicycle, or use public transport instead of a private car. And if you use a private car, then try to use car sharing so as to split the carbon footprint of the car's construction between all its users.
But dirtier during construction. More difficult to repair most of the time too. Pros and cons. If you keep an EV for a long time, than it is cleaner. But a lot of EVs are thrown out instead of being repaired. The real solution is to share cars and, ride a bicycle, walk or use public transport when possible.
> But a lot of EVs are thrown out instead of being repaired
That's not true. There are battery recycling plants going bankrupt because the expected surge of dead EV's didn't materialize. EV's are staying on the road longer than expected, and the batteries are being reused rather than recycled or thrown out.